Support units of the type to which the present invention relate usually consist of an angular contact bearing consisting of two sets of balls and wherein the internal and the external rings are equipped on opposite sides with attachment flanges by which the assembly is mounted to the suspension support of the vehicle and by which the wheel is also fixed to the assembly. In the case of nondriven wheel assemblies, the internal ring of the bearing is replaced by a solid cylindrical element or spindle. In order to accommodate a large number of rolling elements between the rings of the bearing, and thereby to support heavy loads with reduced dimensions, the spindle is usually made in two pieces and one of the raceways is provided on the spindle itself namely the inner raceway for the first set of balls and a second raceway for the second set of balls is provided by a separate ring mounted on the spindle. In the presently known assemblies, this ring is mounted loosely or with a slight play so that the clearance between the raceway and the rolling elements can be checked during the mounting procedure.
British Patent No. 1,570,849 shows a mounting arrangement wherein a ring of the type described above is held in position by half-cones or by a plurality of ring segments with a conical external lateral surface which are supported in a groove in the spindle by a retaining ring integral with the spindle itself. Even though this mounting arrangement is generally satisfactory, there are nevertheless certain disadvantages and drawbacks. For example, by reason of the play between the ring on the internal raceway and the spindle to allow for adjusting gaps between the raceway and the rolling elements, a relative rotational movement takes place between the ring and the half-cones, which leads to premature wear of these elements. This may also occur in a hypothetical situation that it is possible to eliminate the problem of play/ball adjustment and it is consequently possible to force fit the ring on the spindle due to the play that inevitably results in use as a result of wear.